Plant aboveground biomass carbon and nitrogen: Legume Competition Garden

This experiment was established on top of subplots 24, 25 and 26 of E055 (1.2m X 1.2m plots). Sheet metal was installed to divide the subplots into 4 equal parts (subplots are 1.2m x 1.2m, sub-subplots are .6m x .6m). The resulting 12 sub-subplots (4/subplot = 12/plot) were planted according to the following treatments: 1. LC seed on top of established SS 2. AC seed on top of established SS 3. no seed added to established SS 4. PP seed on top of established SS 5. AC seed vs SS seed 6. LC seed vs SS seed 7. PP seed vs SS seed 8. LC seed vs AC seed vs PP seed vs SS seed 9. AC seed 10. LC seed 11. Bare ground (no seeds added) 12. PP seed Where LC=Lespedeza capitata, AC=Amorpha canescens, PP=Petalostemum purpureum, and SS=Schizachyrium scoparium. Equal amounts of MgSO4, CaCO3, P2O5 and K2O are added to the plots each year in early May and Late June. For further information, see fertilization details.本实验以E055地块的24、25、26号副样地（尺寸为1.2m×1.2m）为基础开展。实验人员安装金属隔板，将每个副样地划分为4个均等的子副样地（副样地尺寸1.2m×1.2m，子副样地尺寸0.6m×0.6m）。最终共得到12个子副样地（每个副样地划分4个，即单地块对应12个子副样地），并按照以下处理方案进行播种： 1. 在已定植的SS（Schizachyrium scoparium，须芒草）群落上方播种LC种子 2. 在已定植的SS群落上方播种AC种子 3. 不向已定植的SS群落添加任何种子 4. 在已定植的SS群落上方播种PP种子 5. 以AC种子与SS种子进行对比播种 6. 以LC种子与SS种子进行对比播种 7. 以PP种子与SS种子进行对比播种 8. 以LC、AC、PP、SS四种种子进行组合对比播种 9. 单独播种AC种子 10. 单独播种LC种子 11. 裸地对照组（不添加任何种子） 12. 单独播种PP种子 其中LC为头序胡枝子（Lespedeza capitata），AC为灰毛紫穗槐（Amorpha canescens），PP为紫花佩托斯坦姆草（Petalostemum purpureum），SS为须芒草（Schizachyrium scoparium）。每年5月初与6月末，向各地块施加等量的硫酸镁（MgSO4）、碳酸钙（CaCO3）、五氧化二磷（P2O5）及氧化钾（K2O）。如需了解更多施肥细节，请参阅相关说明。